The present invention relates to a waterproof connector used for the connection of wire harness mounted in a vehicle, and relates to a waterproof plug used for sealing the inside of the connector while being held between the housing of the waterproof connector and an electric wire of the wire harness.
For a related waterproof connector, at the least, the portion whereat male and female terminals engage with each other must be enclosed within in a waterproof space. However, for a waterproof connector having as a function the electrical detection of the engagement of connectors, a terminal that acts in response to the movement of a locking mechanism is provided inside a connector housing, so that the locking mechanism is also enclosed in a waterproof space. For even if a waterproof connector does not have an engagement detector, when it is employed under adverse conditions, mud or dust may become attached to its locking mechanism and prevent the locking mechanism from being easily released. Thus, for such a waterproof connector, the enclosure of the locking mechanism in a waterproof space is also effective.
However, when a locking mechanism is accommodated inside a waterproof space, a problem also arises concerning the time required to unlock it. That is, since release of the locking mechanism must be effected from outside a waterproof seal that defines the waterproof space, some counter measure is required that will permit the mechanism to be unlocked under these conditions.
Waterproof connectors with engagement detectors for which such counter measures are provided are disclosed in Japanese Patent Publications Nos. 9-106852A and 10-270118A.
FIG. 19 is a cross-sectional view of the waterproof connector disclosed in the former publication. In a rear wall of a female connector housing 1a through hole 1b is formed through which is passed a lock arm 1d in which, at its distal end, an engagement hole 1c is formed. To enable the lock arm 1d to be flexibly inclined, it also penetrates and is supported by a waterproof seal 2 that is fitted into the through hole 1b. Riding on the upper portion of the lock arm 1d is an arm responsive terminal 3 that urges the lock arm 1d down towards a projection 4a, formed inside a male connector housing 3; on whose upper face a protrusion 4b and two engagement detection terminals 5 are provided.
When the male connector housing 4 is fitted into the female connector housing 1, its distal end closely contacts the outer face of a waterproof seal 6 located in a portion into which the lock arm 1d is projected, a tightly closed waterproof space S that is defined by the waterproof seal 2. When the connector housings 1 and 4 are normally engaged, the protrusion 4b is fitted into the engagement hole 1c in the lock arm 1d, while the arm responsive terminal 3 contacts the engagement detection terminals 5 and the engagement state is detected by an external circuit.
To release the lock, the lock arm 1d is tilted to the position shown in FIG. 19 by the exertion of a force outside the waterproof space S, i.e., by pushing an external end 1e of the lock arm 1d that extends outward from the waterproof seal 2. Then, the protrusion 4b is disengaged from the hole 1c of the lock arm 1d, and the connector housings 1 and 4 can be separated, releasing the lock. In this unlocking process, the waterproof seal 2 that defines the portion into which the lock arm 1d is inserted permits the tilting of the lock arm 1d. 
FIG. 20 is a cross-sectional view of a waterproof connector disclosed in the latter publication. In the waterproof connector, a female connector housing 7A comprises: a flexible lock arm 7c, which engages a male connector housing 7B when the two connector housings 7A and 7B are normally engaged; and a short-circuit terminal 8A that interacts with the bending of the lock arm 7c. The male connector housing 7B comprises a detection terminal 8B, which interacts with the recovery of the lock arm 7c when the connector housings 7A and 7B are normally engaged, and contacts the short-circuit terminal 8A.
A seal cover 9, which permits the bending of the lock arm 7c and covers its distal end and the short-circuit terminal 8A, is attached to the connector housing 7A. The lock arm 7c and the terminals BA and 8B are accommodated in the waterproof space S that is defined by the seal cover 9.
The waterproof connectors shown in FIGS. 19 and 20 have the following problem, though the release of the lock arms 1d and 7c can be performed from the outside of the waterproof seal 2 and the seal cover 9.
Since the waterproof connector in FIG. 19 is to be unlocked by pushing the external end 1e of the lock arm 1d and by tilting the lock arm 1d, the through hole of the waterproof seal 2 must be formed to permit the lock arm 1d to be tilted. Therefore, water tends to enter through the penetrating portion. Especially when the penetrating portion is composed of elastic material that will permit tilting, the contact force exerted against the lock arm by the waterproof seal 2 is reduced, and the sealing performance is deteriorated.
For the waterproof connector in FIG. 20, the lock arm 7c must be operated through the seal cover 9, so that the operation of the unlocking mechanism is not ideal.
Waterproof connectors are structured to waterproof electric wires connected to the respective terminals inserted by fitting a seal member to each electric wire so as to prevent the entry of water and the like from the outside Otherwise, a plurality of mat-like seal members are integrally formed with electric wire sealing portions to waterproof the whole electric wire by fitting the mat-like seal members to the rear part of a connector housing. The former seal member is called a separate-type waterproof plug, whereas the latter one is called a mat-type waterproof plug.
Japanese Utility Model Publication No. 62-201480U discloses the former separate-type waterproof plug, which will be described with reference to FIG. 21.
The waterproof plug 61 has an insertion hole 62 for receiving an electric wire W and a cylindrical wall 63 surrounding the insertion hole 62. More specifically, the central hole is used as the insertion hole 62, and the peripheral wall is used as the cylindrical wall 63 in order to form an independent tubular body.
The waterproof plug 61 of this kind is normally formed of rubber material such as silicone rubber and NBR, and is formed by rapping molds with the direction of passing the insertion hole 62 therethrough as a rapping direction. Annular convex portions 64 and 65 are also formed on both outer and inner peripheral faces of the cylindrical wall 63 along a peripheral direction crossing the rapping direction.
As shown in FIG. 22, these annular convex portions 64 and 65 are used to make the waterproof plug 61 stick fast to the inner peripheral wall of the insertion hole 67 of a connector housing 66 and to the outer periphery of the electric wire W when the waterproof plug 61 is held between the inner peripheral wall of the insertion hole 67 and the outer periphery of the electric wire W.
However, an excessive force tends to become applied to the related waterproof plug 61 at the time of rapping the product because the annular convex portions 64 and 65 are provided on both the inner and outer peripheral faces of the cylindrical wall 63.
Therefore, though no serious problem arises when rubber material having a high elastic stress marginal value is employed as before, the use of thermoplastic elastomeric resin (e.g., TPEE) having an elastic stress marginal value lower than that of the rubber material may easily make the product undergo plastic deformation at the time of mold opening, thus resulting in poor dimensional stability.
FIG. 23 is a diagram showing a related waterproof connector disclosed in Japanese Patent Publication No. 3-43972A, and FIGS. 24A and 24B are diagrams showing a mat-type rubber plug used for the waterproof connector. In FIG. 23, the waterproof connector, which engages another connector, comprises: a male connector housing 71; female terminals 72, retained in a terminal chamber; and a mat-shaped rubber plug 74, so mounted that it close the rear end opening of the connector housing 71.
Formed in the rubber plug 74 are a plurality of insertion holes 75 through which electric wires 73 are passed that extend to the rear to the female terminals 72. As is shown in FIGS. 13A and 13B, cylindrical walls 76 define the respective through holes 75, and an appropriate flexible force exerted by the cylindrical walls 76 closely attaches them to the outer faces of the electric wires 73 that are passed through the through holes 75. An ensured gap 77, described around the cylindrical walls 76, permits the cylindrical walls 76 to freely expand when the electric wires 73 are passed through the through holes 75 to the female terminals 72.
To fabricate the rubber plug 74 of the related waterproof connector, the cylindrical walls 76 are formed separately, and the ensured space 77, which permits the expansion of the cylindrical walls 76, is described obtained around their periphery. Therefore, since the cylindrical walls 76 can expand freely, the terminals 72 can easily be passed through the through holes 75. However, the strength of the seals that are obtained after the terminals 72 have been inserted depends only the flexibility of the independent cylindrical walls 76, since no member is provided to increase their sealing strength.
Further, since the through holes 75 are defined by the independent cylindrical walls 76, as is shown in FIG. 24B, a pitch P must be set for the through holes 75, while for the cylindrical walls 76 a satisfactory thickness H1 and an adequate intervening space H2, in the gap 77 around the periphery of the cylindrical walls 76, are ensured. As a result, the pitch P is increased, and accordingly, the size of the connector is increased.
While taking the above problems into account, it is the first objective of the present invention to provide a waterproof connector having a superior sealing function and a preferable unlocking function.
It is the second objective of the present invention to provide a waterproof connector that is compactly made and that provides an improved sealing function.
It is the third objective of the present invention to provide a waterproof plug capable of making plastic deformation hardly producible at the time of rapping and also increasing dimensional stability even in a case where any material having a lower elastic stress marginal value, for example, thermoplastic elastomeric resin is used to form the waterproof plug.
In order to achieve the first object, according to the present invention, there is provided a waterproof connector comprising:
a pair of connector housings to be engaged with each other;
a lock member for locking the connector housings at a position where the connector housings are completely engaged;
a seal member for defining a waterproof space which accommodates the lock member, the seal member having a through hole which communicates inside and out of the waterproof space; and
an unlock member sealedly inserted into the through hole so as to be slidable in an insertion direction thereof to unlock the engagement of the housing.
In this configuration, when the unlock member merely slides in the direction in which the waterproof seal is penetrated, the release of the lock member can be effected from outside the waterproof seal. In this case, since the unlock member need only slide in the inserting direction, unlike in the related case wherein tilting is permitted, water is prevented from entering via the through hole in the seal member. Further, since the through hole of the seal member need not be composed of elastic material that will permit tilting, the contact force exerted by the seal member on the unlock member pan be increased, and accordingly, the sealing function enhanced. In addition, since the lock member is moved directly by the unlock member, a precise operation can be easily implemented, unlike the related case where the lock member is controlled via the seal member.
Preferably, one of the connector housings includes a guide member situated adjacent to the seal member for guiding the slide movement of the unlock member. The seal member is made of a material harder than that of the seal member.
In this configuration, since the guide member along which the unlock member slides is provided for the less elastic member that is adjacent to the seal member, the unlock member can be moved linearly and stably. Thus, the lock member can be precisely and easily released, without compromising the integrity of the seal member.
Preferably, one of the connector housings includes a through hole situated adjacent to the seal member. The seal member includes a cylindrical wall portion surrounding the through hole and fitted with the through hole of the connector housing. The cylindrical wall portion is compressed between an outer periphery of the unlock member and an inner wall of the through hole of the connector housing.
In this configuration, the cylindrical wall portion around the through hole of the seal member is compresses by insertion of the unlock member, so that the contact force exerted by the seal member on the connector housing and the unlock member is increased. Therefore, the seal at the portion whereat the unlock member is inserted penetrates can be even more increased.
Preferably, the lock member is a lock arm provided with one of the connector housings, which is flexible between a first position for locking the engagement of the connector housings and a second position for unlocking the engagement. The unlock member slides in the through hole toward inside of the waterproof space to flex the lock arm towards the second position.
In this configuration, since the unlock member slides and flexes the lock arm, the connectors can be unlocked.
Preferably, the sliding direction of the unlock member and the flexing direction of the lock arm is substantially orthogonal. The lock arm is, provided with a slant face for converting the sliding movement of the unlock member into the flexing movement of the lock arm, and converting a restoring movement of the lock arm into a slide-back movement of the unlock member.
In this configuration, since the unlock member be slid so that it pushes against the slant face of the lock arm, the lock arm can be flexed until it is perpendicular to the direction in which the unlock member is slid. Therefore, when the lock arm is so formed that it can be freely flexed vertically, the unlock member can be set so it can be slid forward and backward, and when the unlock member is slid from the rear of the connector housing to the front, the lock arm can be released. Further, when the flexed lock arm is to be returned to its original position, the slant face of the lock arm pushes the unlock member in the sliding direction, so that in particular, members such as a spring for urging the unlock member backward need not be provided.
Preferably, the waterproof connector further comprises a terminal for electrically detecting the engagement condition of the connector housings, which is disposed inside of the waterproof space.
In this configuration, since the terminal formed in the waterproof space interact with the lock member accommodated within the same waterproof space, the terminal can be brought into contact or separated in accordance with the action of the lock member, and the engagement state of the connectors can be obtained by electrically detecting the state of the terminal.
Preferably, a distal end of the unlock member, which abuts against the slant face of the lock arm, is rounded.
In this configuration, since the distal end of the unlock member is rounded, there is minimal contact between the distal end and the slant face, and the sliding movement of the unlock member can be precisely converted into the flexing movement of the lock arm.
Preferably, the slant face includes a groove portion for receiving the distal end of the unlock member.
In this configuration, the distal end of the unlock member always appropriately abuts against the slant face of the lock arm, and does not slide off therefrom.
In order to achieve the second object, according to the present invention, there is provided a waterproof connector comprising:
a connector housing including a plurality of terminal chambers into for respectively accommodating a terminal provided with an electric wire;
a mat-shaped rubber plug attached to a rear end portion of the connector housing, in which recessed portions are formed so as to remain cylindrical protrusions each having a through hole through which the electric wire is inserted; and
a rear holder attached to the rear end portion of the connector housing to retain the rubber plug thereat, the rear holder including projections each configured so as to compress the associated protrusion of the rubber plug in the diameter direction of the electric wire as being inserted into the associated recessed portion of the rubber plug,
wherein the rubber plug includes at least one protrusion block formed by integrating adjacent cylindrical protrusions.
In this case, since the adjacent cylindrical protrusions are formed as integrated blocks, and unlike the related art, do not separately define a gap in the vicinity, the pitch between the through holes can be reduced, so that a compact connector can be made.
Preferably, the waterproof connector further comprises:
a provisional retaining member for provisionally retaining the rear holder onto the connector housing such that the projections of the rear holder does not interfere with the associated protrusions of the rubber plug; and
a retaining member for securely retaining the rear holder onto the connector housing such that the projections interferes the associated projections.
The electric wires are inserted into the associated through holes of the rubber plug when the rear holder is provisionally retained onto the connector housing. Then the rear holder is securely retained onto the connector housing while compressing the protrusions of the rubber plug by the projections of the rear holder.
In this case, since the rear holder can be temporarily held on the connector housing before the projections of the rear holder are pressed into the recessed portion in the rubber plug, the protrusions in the rubber plug are permitted to expand freely, so that the efficiency of the operation when the terminals are inserted can be improved without the rear holder having to be held in place by hand. Further, since the rear holder can be securely held on the connector housing after the projections of the rear holder have been pressed into the recessed portion of the rubber plug, the state where the rubber plug and the electric wires more closely contact each other can be stably maintained for an extended period of time, and the reliability of the sealing can be enhanced.
In order to achieve the third object, according to the present invention, there is provided a waterproof plug molded by a rapping mold, comprising:
a cylindrical wall portion surrounding a through hole extending in the rapping direction, to which an electric wire is inserted; and
an annular convex formed on one of an inner face and an outer face of the cylindrical wall portion so as to extend in a direction perpendicular to the rapping direction,
wherein the other one of the inner face and the outer face of the cylindrical wall portion is made straight with regard to the rapping direction.
In this configuration, the mold on the part of straight face is drawn first and then the mold on the part of annular convex is drawn, so that no excessive force is applied to the waterproof plug when the mold on the part of straight face is drawn. When the mold on the part of annular convex is drawn, free deformation is permitted as the opposed side face is released, whereby no excessive force is applied to the waterproof plug at the time of rapping. In other words, no excessive force is applied to the waterproof plug in either case of drawing on the outer face or inner face of the cylindrical wall portion. Therefore, plastic deformation at the time of rapping is preventable even in a case where any material having a low elastic stress marginal value is employed. Thus, dimensional stability can be increased.
Preferably, the plug is provided as an individual cylindrical plug a central hole of which serves as the through hole.
The waterproof plug is of a so-called separate type in which it is inserted separately into the through hole between the electric wire and the housing. In a waterproof plug of this type, dimensional stability can be improved as plastic deformation is preventable at the time of rapping even in a case where the waterproof plug is molded from a material having a low elastic stress marginal value.
Preferably, a plurality of cylindrical portions are formed on a mat-shaped seal member. The annular convex is formed on each inner face of the cylindrical portions.
This waterproof plug is of a so-called mat-type in which the gap between the whole electric wire and the connector housing is sealed by fitting the waterproof plug to the rear end of the connector housing. In a waterproof plug of this type, dimensional stability can be improved as plastic deformation is preventable at the time of rapping even in a case where the waterproof plug is molded from a material having a low elastic stress marginal value.
Preferably, the plug is made of a thermoplastic elastomeric resin.
The thermoplastic elastomeric resin is a material having properties of xe2x80x9cthermoplastic resinxe2x80x9d simultaneously with xe2x80x9crubberxe2x80x9d and by using the thermoplastic elastomeric resin to form the waterproof plug, it is possible to decrease the molding time greatly in comparison with the related rubber materials (e.g., silicone rubber and NBR).